The answer is yes you can, you can manipulate the entire object model from .net and both create a package from scratch in the object model and I believe execute it there..

It might make sense to create the package and then write it out to a file as a completed product ready to run, if you are going to go through the trouble of manipulating it at the object level it might make more sense but I would need a bit more data to give you a better answer..

CEWII